Mailed participant reminders are associated with improved colonoscopy uptake after a positive FOBT result in Ontario’s ColonCancerCheck program

BACKGROUND: Timely follow-up of fecal occult blood screening with colonoscopy is essential for achieving colorectal cancer mortality reduction. This study evaluates the effectiveness of two ongoing interventions designed to improve colonoscopy uptake after a positive fecal occult blood test (FOBT) result within Ontario’s population-wide ColonCancerCheck program. The first was a revision of mailed FOBT lab results to physicians to explicitly define a positive FOBT and to recommend colonoscopy. The second was a letter to participants informing them of the positive FOBT and urging them to seek appropriate follow-up. METHODS: Prospective cohort study using Ontario’s ColonCancerCheck program data sets (2008–2011), linked to provincial administrative health databases. Crude rate ratios were calculated to assess determinants of colonoscopy uptake among an Ontario-wide FOBT-positive cohort with rolling enrolment, followed from October 2008 through February 2011. Segmented time-series regression was used to assess the average additional change in colonoscopy uptake after FOBT-positive status following the introduction of two ongoing interventions among the same cohort. RESULTS: A notification mailed directly to FOBT-positive screening participants was observed to increase colonoscopy uptake, beyond the modest average underlying increase throughout the study period, by an average of 3% per month (multivariable-adjusted RR: 1.03, 95% CI: 1.00–1.06). However, revision of the existing FOBT result notification to physicians was observed to have no effect. CONCLUSIONS: Direct participant notification of a positive FOBT result improved adherence with follow-up colonoscopy in Ontario’s population-wide ColonCancerCheck program. Further participant-directed interventions may be effective means of maximizing adherence in population-wide screening. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13012-015-0226-0) contains supplementary material, which is available to authorized users.